Growth of Boron-Rich Nanowires by Chemical Vapor Deposition (CVD)

Abstract

B-rich nanowires are grown on Ni coated oxidized Si(111) substrate using diborane as the gas precursor in a CVD process at 20 torr and900C∘. These nanowires have diameters around 20–100 nanometers and lengths up to microns. IcosahedronB12is shown to be the basic building unit forming the amorphous B-rich nanowires as characterized by EDAX, XRD, XPS, and Raman spectroscopies. The gas chemistry at low [B2H6]/ [N2] ratio is monitored by the in situ mass spectroscopy, which identifiedN2as an inert carrier gas leading to formation of the B-rich compounds. A nucleation controlled growth mechanism is proposed to explain the rugged nanowire growth of boron. The role of the Ni catalyst in the synthesis of the B-rich nanostructures is also discussed.